Field of the Invention
The present invention relates to an ink jet recording apparatus and an ink jet recording method.
Description of the Related Art
In an ink jet recording technique, an image is formed by applying a liquid composition (ink) including a coloring material directly or indirectly onto a recording medium. At this time, curling or cockling occurs because of excessive absorption of liquid components in the ink by the recording medium.
To prevent such a problem, there have been proposed techniques for quickly removing a liquid component in the ink, such as a technique of drying a recording medium with, for example, warm air or infrared rays, and a technique for forming an image on a transfer body, drying liquid components included in the image on the transfer body with, for example, thermal energy, and then transferring the image onto a recording medium such as paper.
Another proposed technique for removing liquid components included in an image on a transfer body is a technique of bringing a roller-shaped porous body into contact with an ink image to absorb and remove liquid components from the ink image without using thermal energy (see Japanese Patent Application Laid-Open No. 2009-045851).
Still another proposed technique is a technique of bringing a belt-shaped polymeric absorbent into contact with an ink image to absorb and remove liquid components from the ink image (see Japanese Patent Application Laid-Open No. 2001-179959).
Yet another proposed technique is a method of pressing a plurality of porous rollers against an intermediate transfer member under the same pressure in which the pore diameter or the aperture ratio of each porous roller is varied (Japanese Patent Application Laid-Open No. 2009-000915). This document mentions that as the pore diameter decreases, the capillary pressure increases, and the absorption amount is increased by reducing the pore diameter of a porous body that comes into contact with the image at the second time or later.
As described in this document, in a case where a roller- or belt-shaped liquid absorbing member is used for absorption and removal of a liquid component from an image, a nip in which the liquid absorbing member and an ink receiving medium contact each other is formed, and an image is caused to pass through the nip, thereby performing a liquid absorbing treatment.
In an image treatment in which a liquid component included in an image is absorbed by a porous body of a liquid absorbing member, a capillary pressure of the porous body plays an important role in intake of the liquid components into the porous body. In a state where an image contains a large content of liquid components and the content of the liquid components is large in an initial state of image fixation depending on image formation conditions, a polymeric absorbent as described in Japanese Patent Application Laid-Open No. 2001-179959 fails to obtain a sufficient effect of absorbing the liquid component in some cases.
In addition, in the case of using a porous body described in Japanese Patent Application Laid-Open No. 2009-045851 or Japanese Patent Application Laid-Open No. 2009-000915, in a state in which the content of the liquid components is large in an initial stage of image fixation, the liquid components in an image cannot be efficiently absorbed only by using a capillary pressure of the porous body in some cases. In particular, in a recording method in which a reaction liquid is caused to react to reduce bleeding and beading so that an aggregation including a coloring material is formed in an image, the image itself structurally has a capillary force, and an insufficient absorption amount is likely to be obtained only by using a simple capillary pressure of the porous body.
In such a case as described above, it is effective to use a pressure in pressing a porous body against an image together with a capillary pressure. In this case, it is necessary to increase a liquid component absorption amount, which is the amount of liquid components in an image absorbed by the porous body, to enhance a force of pressing the porous body against the image so that liquid components forced out of the image can be efficiently absorbed in the porous body.
In a state where the content of liquid components is large in an initial stage of image fixation, however, an image includes a coloring material insufficiently fixed onto an ink receiving medium. Thus, when a porous body is pressed against an image under a high pressure, the coloring material might adhere to the porous body. In addition, if an image deforms or is crushed under a high pressing force, an opportunity of contact between the coloring material in the image and the porous body increases, facilitating adhesion of the coloring material in some cases.
Accordingly, in the case of additionally using a pressing force in absorbing a liquid component included in an image by a porous body, there arises a technical objective of efficiently absorbing the liquid component while reducing adhesion of the coloring material. The patent documents described above, however, neither disclose nor suggest this technical objective.
The present invention has been made in view of the foregoing problems, and has an object of providing an image forming technique that enables image formation with high image quality by obtaining a large absorption amount with reduced adhesion of a coloring material with respect to a porous body in absorbing liquid components included in an image by the porous body to promote image fixation.